Tetraploid black locust （Robinia pseudoacacia） is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant f...Tetraploid black locust （Robinia pseudoacacia） is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant forage. However, currently no stock- breeders have adopted it as a major forage in China and other countries for a lack of information on the evaluation of nutritional ingredients of leaves and stems of young tetraploid black locust （YTBL） by in situ digesting tests. The objectives of this study were： 1） to assess the nutritive value of YTBL that bourgeoned from root stumps in the spring by determining the ruminal in situ disappearance kinetics of dry matter （DM）, organic matter （OM）, crude protein （CP）, ether extract （EE）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） from leaves, stems and a mixture of both leaves and stems （MLS） of YTBL; 2） to compare these kinetic estimates with those of Leymus chinensis, a widely used ruminant forage in China. All samples were evaluated in situ by using five ruminally cannulated crossbred steers （550±22.7 kg BW）. The results of 48 hours, the representative incubation period, indicate that in situ disappearance rates of DM and OM in YTBL leaves, stems and MLS are on average about 40% and can attain the level of digestibility of L. chinensis. In situ disappearance rates of leaves, stems and MLS of YTBL for CP and EE were 41% and 58% respectively, rates higher than those of L. chinensis. But the disappearance rates of NDF and ADF were, on average, respectively 30.62% and 24.89% and lower than those ofL. chinensis. By analyzing synthetically all of our results it could be inferred that MLS of YTBL offers effective ruminal degradability of DM, NDF, ADF, CP, EE and OM, similar to the nutrients of L. chinensis. This supports our contention that the YTBL leaves, stems and MLS are suitable feed for those ruminants requiring high levels of nutrients, such as dairy cows and Boer goats, instead of plant forage, which is decidedly lacking in some parts of the world.展开更多
Differences in drought tolerance were studied among three strains of black locust(Robinia pseudoacacia L.) clones(one-year-old micropropagated K2,K3 clones and a common diploid clone CK) under simulated natural drough...Differences in drought tolerance were studied among three strains of black locust(Robinia pseudoacacia L.) clones(one-year-old micropropagated K2,K3 clones and a common diploid clone CK) under simulated natural drought conditions.The experiment was carried out as a randomized complete blocks design.The following physiological variables were examined,biomass and allocation,photosynthetic characteristics,i.e.net photosynthetic rate(Pn),transpiration rate(E),stomatal conductance(Gs),intercellular CO2 concentration(Ci),instantaneous water use efficiency(WUEI),and long-term water use efficiency(WUEL).Results showed that the K2 and K3 had greater biomass,with the K3 displaying favorable ratio of root biomass to shoot and leaf biomass.Net photosynthetic rate(Pn) declined along with Gs,Ci and the ratio intercellular/ambient(Ci/Ca),under increasing drought stress.The decline in photosynthesis was mainly due to stomatal limitation.The K2 and K3 showed higher WUE and Pn than the CK.There were significant differences of drought level on WUEL,and the WUEL of K2 and K3 was greater than that of CK.Evaluation based overall physiological characteristics indicates the K2 and K3 are more drought tolerant,which are well adapted to the drought-stricken area of Northwest China.展开更多
基金supported by the Ministry of Science and Technology of China (Grant No. 003EFN216700307)the State Forestry Admini-stration of China (No. 2003–5–2)
文摘Tetraploid black locust （Robinia pseudoacacia） is a woody plant with larger leaves and richer nutritional content than normal diploid black locust, with greater biomass and wider adaptability than herbaceous plant forage. However, currently no stock- breeders have adopted it as a major forage in China and other countries for a lack of information on the evaluation of nutritional ingredients of leaves and stems of young tetraploid black locust （YTBL） by in situ digesting tests. The objectives of this study were： 1） to assess the nutritive value of YTBL that bourgeoned from root stumps in the spring by determining the ruminal in situ disappearance kinetics of dry matter （DM）, organic matter （OM）, crude protein （CP）, ether extract （EE）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） from leaves, stems and a mixture of both leaves and stems （MLS） of YTBL; 2） to compare these kinetic estimates with those of Leymus chinensis, a widely used ruminant forage in China. All samples were evaluated in situ by using five ruminally cannulated crossbred steers （550±22.7 kg BW）. The results of 48 hours, the representative incubation period, indicate that in situ disappearance rates of DM and OM in YTBL leaves, stems and MLS are on average about 40% and can attain the level of digestibility of L. chinensis. In situ disappearance rates of leaves, stems and MLS of YTBL for CP and EE were 41% and 58% respectively, rates higher than those of L. chinensis. But the disappearance rates of NDF and ADF were, on average, respectively 30.62% and 24.89% and lower than those ofL. chinensis. By analyzing synthetically all of our results it could be inferred that MLS of YTBL offers effective ruminal degradability of DM, NDF, ADF, CP, EE and OM, similar to the nutrients of L. chinensis. This supports our contention that the YTBL leaves, stems and MLS are suitable feed for those ruminants requiring high levels of nutrients, such as dairy cows and Boer goats, instead of plant forage, which is decidedly lacking in some parts of the world.
文摘Differences in drought tolerance were studied among three strains of black locust(Robinia pseudoacacia L.) clones(one-year-old micropropagated K2,K3 clones and a common diploid clone CK) under simulated natural drought conditions.The experiment was carried out as a randomized complete blocks design.The following physiological variables were examined,biomass and allocation,photosynthetic characteristics,i.e.net photosynthetic rate(Pn),transpiration rate(E),stomatal conductance(Gs),intercellular CO2 concentration(Ci),instantaneous water use efficiency(WUEI),and long-term water use efficiency(WUEL).Results showed that the K2 and K3 had greater biomass,with the K3 displaying favorable ratio of root biomass to shoot and leaf biomass.Net photosynthetic rate(Pn) declined along with Gs,Ci and the ratio intercellular/ambient(Ci/Ca),under increasing drought stress.The decline in photosynthesis was mainly due to stomatal limitation.The K2 and K3 showed higher WUE and Pn than the CK.There were significant differences of drought level on WUEL,and the WUEL of K2 and K3 was greater than that of CK.Evaluation based overall physiological characteristics indicates the K2 and K3 are more drought tolerant,which are well adapted to the drought-stricken area of Northwest China.
